Author Topic: TS "Javier" rainfall in Tucson, AZ  (Read 975 times)

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Offline Old Tele man

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TS "Javier" rainfall in Tucson, AZ
« on: August 09, 2016, 02:14:50 PM »
So far, rainfall from TS "Javier" in NW Tucson has been:

0845-1150 = 0.87-inches.



What have other areas in Tucson collected?
« Last Edit: August 09, 2016, 03:45:37 PM by Old Tele man »
SYS: Davis VP2/WL-IP & Envoy8X/WL-USB
CWOP: DW6988 - 2 miles NNE of Cortaro, AZ
WU - KAZTUCSO202, Countryside

Offline CW2274

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Re: TS "Javier" rainfall in Tucson, AZ
« Reply #1 on: August 09, 2016, 04:25:31 PM »
1.71" for me. =D> Tons of road closures. Let's see what tomorrow brings when the good stuff gets here!
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Offline CW2274

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Re: TS "Javier" rainfall in Tucson, AZ
« Reply #2 on: August 09, 2016, 05:55:11 PM »
What RH% did you get to during today's rainfalls? I got to 94%RH, which calculates to be about 2% low:

Ta = 68.2F, Tdp = 67F, and RH = 94% (calculates to 95.88%)
Ta = 69.2F, Tdp = 68F, and RH = 94% (calculates to 95.99%)
Wow, that's weird, I had 96% for 1 1/2 hr with the exact temp/dew spread of 1.2F. So according to your calculation and my console, it's right, but yours is wrong. How is that?
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Offline CW2274

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Re: TS "Javier" rainfall in Tucson, AZ
« Reply #3 on: August 09, 2016, 06:44:52 PM »
What RH% did you get to during today's rainfalls? I got to 94%RH, which calculates to be about 2% low:

Ta = 68.2F, Tdp = 67F, and RH = 94% (calculates to 95.88%)
Ta = 69.2F, Tdp = 68F, and RH = 94% (calculates to 95.99%)
Wow, that's weird, I had 96% for 1 1/2 hr with the exact temp/dew spread of 1.2F. So according to your calculation and my console, it's right, but yours is wrong. How is that?
I'm still using the SHT15 sensor; the SHT31 sensor hasn't been installed yet because of the on-going "Low Battery on Station 1" error message.
Oh. I thought the console did the calculation, not the sensor itself. Still odd. Another reason to love the 31! Get er' done! UU
Davis Wireless VP2 SHT31 24hr 67CFM FARS
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Offline CW2274

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Re: TS "Javier" rainfall in Tucson, AZ
« Reply #4 on: August 09, 2016, 08:15:00 PM »
Oh. I thought the console did the calculation, not the sensor itself. Still odd. Another reason to love the 31! Get er' done! UU
You are correct, but the Ta and RH% values originate from the sensor, so if they're off even slightly, then the *calculated* dewpoint temperature (Tdp) is off too. I used the Julius F Bosen approximation equation, which is surprisingly accurate:

RH% = 100%*[ (173 - 0.1*Ta + Tdp) / (173 + 0.9*Ta) ]^8
That is soooo far above my pay grade, I'll just say #-o
Davis Wireless VP2 SHT31 24hr 67CFM FARS
RW Tipper w/ CoCoRaHS